1. Field
Embodiments disclosed herein relate to an oil supply structure of a hermetic reciprocating compressor in which a compression mechanism for compressing a refrigerant by a reciprocating motion of a piston and an electric motor-operated mechanism for generating a driving force are formed as one body and are accommodated in a sealing case.
2. Description of the Related Art
In general, a compressor, as an element of a refrigerating cycle device, for example a refrigerator, air conditioner, or a heat pump, is a device that compresses a refrigerant at a high temperature under a high pressure. The compressor may be classified into various types of compressors according to a compression method and a sealing structure. Among these, a hermetic reciprocating compressor refers to a compressor that includes a compression mechanism for compressing a refrigerant by a reciprocating motion of a piston and an electric motor-operated mechanism for driving the compression mechanism and in which the compression mechanism and the electric motor-operated mechanism are installed in one sealing case.
Such a hermetic reciprocating compressor includes a rotation shaft for transferring a driving force of the electric motor-operated mechanism to the compression mechanism. Oil for lubricating and cooling elements of each mechanism may be stored in a lower portion of the sealing case, and an oil supply structure may be disposed on the rotation shaft and allow the oil to ascend so as to supply the oil to each element.
As an example of the compressor, a hermetic compressor is disclosed in Korean Patent Laid-open Publication No. 10-2005-0052011. According to the disclosure, an internal path that allows oil to ascend is formed in a lower portion of a rotation shaft, and a spiral groove is formed in an outer circumferential surface of an upper portion of the rotation shaft and connected to the internal path. Also, spiral wings and a guide cap are disposed on the lower portion of the rotation shaft of the compressor and guide the oil stored in a sealing case to the internal path.
Through the structure, the oil stored in a lower portion of the sealing case is picked up by the spiral wings and the guide cap and ascends by passing through the internal path formed in the lower portion of the rotation shaft and the spiral groove formed in the outer circumferential surface of the upper portion of the rotation shaft successively.
However, since the rotation shaft of the compressor disclosed in the above publication requires processing of the internal path, the spiral groove formed outside the rotation shaft, and a communication hole through which the internal path and the spiral groove communicate, processing of the rotation shaft is complicated. In addition, since the guide cap formed in the lower portion of the rotation shaft rotates together with the rotation shaft, this causes vibration of an oil level and associated noise results from the vibration.